What wonderful comments! What I think is interesting about them is that the two theories suggested are totally different. One person thinks it is a fish, and another thinks it is a mammal! These are totally different classes of organisms!

(We'll talk later about how scientists classify living organisms. This is an important and helpful system to know.)

Here is my challenge to you:

How will you check these theories?

and

When you have checked them, please share if you think the theory is correct or not, and why (show your evidence).